<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .red {
            color: red;
        }

        p {
            color: yellow;
        }

        #blue {
            color: blue;
        }

        * {
            font-size: 30px;
        }
    </style>
</head>

<body>
    <!-- 
        基本选择器
        1.标签选择器
        2.类选择器
        3.id选择器
        4.通配符选择器
     -->

    <div>
        <p>111</p>
    </div>

    <div class="red">111</div>

    <div id="blue">222</div>
</body>

</html>